While I am a Playstation Fanboy, I always also buy the Nintendo consoles for a few select games. I can comfortably say that the Nintendo DS has an astonishing library, enough to edge the PSP for me. We really undervalued how amazing the library offering for DS and PSP were -> just not the same for me in the 3DS + VITA era. Get both is my conclusion, but DS edges for me.
PSN: Saugeen-Uwo Feel free to add me (put Vg Chartz as MSG)!
Nintendo Network ID: Saugeen-Uwo